AUSAM/source/S/tr.c

int dflag 0;
int sflag 0;
int cflag 0;
int save 0;
char code[256];
char squeez[256];
char vect[256];
struct string
{
	int last, max, rep;
	char *p;
} string1, string2;
int inbuf[259];

main(argc, argv)
char **argv;
{
	register int i, j, c, d;
	char *compl;
	extern fout;

	string1.last = string2.last = 0;
	string1.max = string2.max = 0;
	string1.rep = string2.rep = 0;
	string1.p = string2.p = "";

	if(--argc > 0)
	{
		argv++;
		if(*argv[0] == '-' && argv[0][1] != 0)
		{
			while(*++argv[0])
				switch(*argv[0])
				{
				case 'c':
					cflag++;
					continue;
				case 'd':
					dflag++;
					continue;
				case 's':
					sflag++;
					continue;
				}
			argc--;
			argv++;
		}
	}
	if(argc > 0)
		string1.p = argv[0];
	if(argc > 1)
		string2.p = argv[1];
	if(cflag)
	{
		while(c = next(&string1))
			vect[c&0377] = 1;
		j = 0;
		for(i = 1; i < 256; i++)
			if(vect[i] == 0)
				vect[j++] = i;
		vect[j] = 0;
		compl = vect;
	}
	for(;;)
	{
		if(cflag)
			c = *compl++;
		else
			c = next(&string1);
		if(c == 0)
			break;
		d = next(&string2);
		if(d == 0)
			d = c;
		code[c&0377] = d;
		squeez[d&0377] = 1;
	}
	while(d = next(&string2))
		squeez[d&0377] = 1;
	squeez[0] = 1;
	for(i = 0; i < 256; i++)
	{
		if(code[i] == 0)
			code[i] = i;
		else if(dflag)
			code[i] = 0;
	}

	inbuf[0] = 0;
	fout = dup(1);
	close(1);
	while((c = getc(inbuf)) >= 0)
	{
		if(c == 0)
			continue;
		if(c = code[c&0377]&0377)
			if(!sflag || c != save || !squeez[c&0377])
				putchar(save = c);
	}
	flush();
}

next(s)
register struct string *s;
{
	register int a, b, c, n, base;

	if(--s->rep > 0)
		return(s->last);
	if(s->last < s->max)
		return(++s->last);
	if(*s->p == '[')
	{
		nextc(s);
		s->last = a = nextc(s);
		s->max = 0;
		switch(nextc(s))
		{
		case '-':
			b = nextc(s);
			if(b < a || *s->p++ != ']')
				goto error;
			s->max = b;
			return(a);
		case '*':
			base = (*s->p == '0')?8:10;
			n = 0;
			while((c = *s->p) >= '0' && c < '0'+base)
			{
				n = base*n+c-'0';
				s->p++;
			}
			if(*s->p++ != ']')
				goto error;
			if(n == 0)
				n = 1000;
			s->rep = n;
			return(a);
		default:
		error:
			write(1, "Bad string\n", 11);
			exit();
		}
	}
	return(nextc(s));
}

nextc(s)
register struct string *s;
{
	register int c, i, n;

	c = *s->p++;
	if(c == '\\')
	{
		i = n = 0;
		while(i < 3 && (c = *s->p) >= '0' && c <= '7')
		{
			n = n*8+c-'0';
			i++;
			s->p++;
		}
		if(i > 0)
			c = n;
		else
			c = *s->p++;
	}
	if(c == 0)
		*--s->p = 0;
	return(c&0377);
}